Process for regulating a clutch

Abstract

In a process for regulating a clutch which is situated within a power train between an input shaft (22) and an output shaft (24), the rotation-rate differences Δω of the power train are detected via a sensor device. With the use of regulating equipment and depending on a control variable x, a correcting variable y which affects the speed difference Δn is controlled. To provide regulating equipment at favorable construction cost, the regulating equipment has a comparator unit (51) in which an actual value x of the rotation-rate difference Δω in the power train behind the clutch (21) is compared with a preset fixed limited value w const , the rotation-rate difference Δω being limited to the limit value w const by changing the correcting variable of the clutch (21) upon reaching or exceeding the limit value w const .

We claim: 
     
       1. A process for regulating a clutch situated in a power train between an input and an output shaft to reduce unwanted noise occurring therein, in which a sensor device (55, 56) is provided for detecting a rotation-rate difference Δω in the power train and regulating equipment (52), depending upon a control variable detected by the sensor device, controls a correcting variable y to be fed to the clutch to control a speed difference Δn to reduce unwanted power train noise, the process comprising the steps of: providing the regulating equipment (52) with a comparator unit (51), and comparing with said comparator unit (51) an actual value x of the rotation-rate difference Δω detected for the output shaft of the power train with a limit value w const , and   limiting the rotation-rate difference Δω to the limit value w const , upon the equal value x at least of reaching and exceeding the limit value w const , by changing the correcting variable y of the clutch (21).   
     
     
       2. A process for regulating a clutch according to claim 1 further comprising the step of: providing an additional first signal path through which during quick changes of the engine load, a delayed change of the control variable and a retarded change of the clutch engaging force can be compensated, by an adaptation value (74), a time-function element (74a) and a differential element (80); and   the adaptation value (74) and the time-function element (74a) acting as a delayed proportional element and simulating a dynamically delayed behavior of the control variable and of the clutch engaging force.   
     
     
       3. A process for regulating a clutch according to claim 1, further comprising the step of: connecting said clutch to an internal combustion engine via the input shaft, and   coordinating, in the regulating equipment (64), a certain correcting variable y with each value of engine load α DK  of the internal combustion engine (47).   
     
     
       4. A process for regulating a clutch according to claim 1, further comprising the step of: providing an additional first signal path through which, during quick changes of the engine load, a delayed change of the control variable and a retarded change of the clutch engaging force can be compensated by an adaptation value (74), a time-function element (74a) and a differential element (80); and   the adaptation value (74) and the time-function element (74a) acting as a delayed proportional element and simulating a dynamically delayed behavior of the control variable and of the clutch engaging force.   
     
     
       5. A process for regulating a clutch according to claim 1, wherein the clutch is shifted in parallel with a hydrodynamic torque converter located a power train (23) between an internal combustion engine (47) and a transmission (48), further comprising the step of: automatically biasing the clutch (21) into a disengaged position when one of the a temperature of water of the internal combustion engine (47) and a temperature of oil of the transmission (48) falls below a first temperature limit value.   
     
     
       6. A process for regulating a clutch according to claim 5, further comprising the step of: providing a second temperature limit value above the first temperature limit value; and   increasing the speed difference Δn in the clutch (21) when operating the water of the internal combustion engine and the oil of the transmission between the first and the second temperature limit values.   
     
     
       7. A process for regulating a clutch according to claim 1, further comprising the step of: limiting the speed difference Δn between the input and the output shafts (22 and 24 or 49) to one of a maximum value Δn max  and a maximum slip duration.   
     
     
       8. A process for regulating a clutch according to claim 7, further comprising the step of: upon one of reaching and exceeding one of the maximum value Δn max  and the maximum slip duration, varying the limit value w const  by a correction value K, depending on an engine load of the internal combustion engine.   
     
     
       9. A process for regulating a clutch according to claim 8, further comprising the step of: continuously comparing, in the comparator unit (62), the actual value x of the speed difference Δn with a desired value w which corresponds to a very small rotation-rate difference Δω; and   feeding any error x w  resulting therefrom to the regulating equipment (64) which has a proportional part and an integral part.   
     
     
       10. A process for regulating a clutch according to claim 9, further comprising the step of: changing the proportional part of the regulating equipment, according to the engine load α DK , so that the proportional part becomes greater as the engine load increases.   
     
     
       11. A process for regulating a clutch according to claim 9, further comprising the step of: changing the integral part of the regulating equipment, so as to reinforce control of the integral part, depending upon one of the error x w , the engine load α DK  and quick changes in engine load α DK .   
     
     
       12. A process for regulating a clutch according to claim 9, further comprising the step of: changing the proportional part according to a load-change speed α DK  such that the proportional part becomes greater as the load-change speed α DK  increases.   
     
     
       13. A process for regulating a clutch according to claim 12, further comprising the step of: forming the proportional part according to the error x w  of the comparator unit (62) such that the proportional part becomes greater with greater errors x w .   
     
     
       14. A process for regulating a clutch situated in a power train of a motor vehicle to reduce unwanted droning and buzzing noise occurring therein, the clutch being situated in the power train between an input shaft (22), connected with an internal combustion engine (47), and an output shaft (24), connected with a transmission unit (48), including a pickup device for detecting a speed difference Δn of the input and output shafts (22 and 24), a sensor device for detecting a rotation-rate difference Δω and regulating equipment (64), depending upon a control variable x measured by the pickup device, controlling a correcting variable y to be fed to the clutch (21) to control the speed difference Δn to reduce unwanted power train droning and buzzing noise, the process comprising the steps of: feeding operational parameters of the internal combustion engine (47), which cause the rotation-rate differences Δω in the power train, to a first pickup (63) coordinated with the regulating equipment (64) and, based on the operational parameters, the first pickup (63) generating a first desired value w of the speed difference Δn;   feeding the first desired value w and the control variable x to a comparator unit (62) of the regulating equipment (64); and   measuring and feeding the rotation-rate difference Δω to a second desired-value pickup (66), and   feeding a second desired value w, depending upon whether the rotation-rate difference Δω is one of below, above or at a limit value of the rotation-rate difference Δω, to one of the comparator unit (62) and to the first pickup (63) adaptively controlling the first desired value w thereof.   
     
     
       15. A process for regulating a clutch according to claim 14, further comprising the step of: lowering the control variable y via a second signal path with a preset temporary gradient when the speed difference Δn falls below a desired value and additionally falls below a threshold value lying below the desired value.   
     
     
       16. A process for regulating a clutch according to claim 14, further comprising the step of: providing a pickup element which detects a torque flow T M  of the clutch during at least one of a traction and a coasting operation; and   when no torque flow T M  is present, setting the correcting variable y to zero, from where the control again starts as a new torque buildup occurs.   
     
     
       17. A process for regulating a clutch according to claim 14 further comprising the step of: detecting engine load of the internal combustion engine (47) as an operational parameter; and   changing the correcting variable y of the clutch (21), to an increased speed difference Δn when the engine load is below a certain valve of the engine load in a traction and a coasting operation of the motor vehicle.   
     
     
       18. A process for regulating a clutch according to claim 17, further comprising the step of: detecting a load-change speed α DK  of the internal combustion engine (47); and when exceeding a maximum value α DK  max of the load-change speed,   increasing a desired value of the speed difference Δn of the input and output shafts (22 or 24) when the engine load diminishes, and decreasing a desired value of the speed difference Δn of the input and the output shafts (22 or 24) when the engine load is one of increased and kept constant.   
     
     
       19. A process for regulating a clutch according to claim 14, further comprising the step of: coordinating, in the regulating equipment (64), a certain correcting variable y with each value of the engine load α DK  of internal combustion engine (47).   
     
     
       20. A process for regulating a clutch according to claim 19 further comprising the step of: continuously correcting a static coordination between the value of the engine load α DK  and the control variable y corresponding to an engaging force of the clutch (21) such that, at a stationary operation point, the speed difference Δn for a predetermined period of time reaches a desired value; and   resetting of the control variable x to a desired value with the regulating equipment even when the static coordination between the value of the engine load α DK  and the control variable y has shifted and wherefrom are deduced changed needed for an adaptive coordination between the engine load α DK  and the control variable y.   
     
     
       21. A process for regulating a clutch according to claim 14, in which the clutch is shifted in parallel with hydrodynamic torque converter located a power train (23) between the internal combustion engine (47) and the transmission (48), further comprising the step of: automatically biasing the clutch (21) into a disengaged position when one of a temperature of water of the internal combustion engine (47) and a temperature of oil of the transmission (48) falls below a first temperature limit value.   
     
     
       22. A process for regulating a clutch according to claim 21 further comprising the step of: providing a second temperature limit value above the first temperature limit value; and   increasing the speed difference Δn in the clutch (21) when operating the water of the internal combustion engine and the oil of the transmission between the first and the second temperature limit values.   
     
     
       23. A process for regulating a clutch according to claim 21, further comprising the step of: providing a second temperature limit value above the first temperature limit value; and   canceling a preset speed difference Δn, according to a defined characteristic line, when the first temperature limit value is exceeded.   
     
     
       24. A process for regulating a clutch according to claim 21, further comprising the step of: providing, for a short duration after starting, information regarding at least one of the engine oil temperature and the engine water temperature to the regulating equipment (64) from a control electronic system of the internal combustion engine (47); and   setting, according to this information, a time-dependent characteristic line according to which an increased speed difference Δn is canceled.